Chromatography Forum

Does 100ppm fat in the ethyl acetate mess up the chromatogram?

I'd think large molecules like the triglycerides would simply remain primarily in the liner, or on the first portion of the column. Of course, such residues will build up over time.

chromatogram of what? Can you run a standard with your target analytes without the fat for comparison?

My guess is that you'll have plenty of interfering peaks working in SIM and that it will impossible to work in SCAN. What I know for sure is that it will completely foul your injector, and very possibly, your column. I know because I tried.

Caveat emptor

It is definately preferable to avoid introducing fat into the GC either by headspace, saponification of the sample matrix, or SPE. If all else fails dilute the sample enough to minimize it and use either an inverted cup or liner with wool and rinse it routinely.

With fat you will most likely start seeing palmitic and stearic acid squalene and octadecadienal (other large aldehdes) as it decomposes in the injector and eventually peak tailing.

I deal with fat all the time so I know. As a last resort I keep a mediocre db-5 column and crapo liner arround for instances where I can't avoid injecting it.